In the operation of electrolytic cells, including fuel cells, it is advantageous to balance the pressure between a gas and a liquid electrolyte within the pores of a porous gas electrode so that a three-phase reaction between liquid, gas, and electrode can take place. It is also advantageous to operate electrolytic cells at high temperatures and pressures, because high temperatures and pressures enhance the sought-after three-phase reaction. However, there are several disadvantages in operating high-pressure electrolytic cells with static liquid electrolyte.
In the operation of electrolytic cells, the liquid electrolyte is depleted as a result of the reaction of the cell and requires recharging. Further, the electrolyte may become contaminated with the by-products of the cell reaction and require treatment to remove the contaminants. Also, the resulting product of the cell reaction may be suspended in the electrolyte and must be removed from the electrolyte.
In the operation of a high temperature and pressure cell in which the liquid electrolyte is stationary, the cell must be shut down whenever the liquid electrolyte needs to be recharged, treated or replaced. Once the electrolyte has been treated or recharged, the cell will not operate at peak performance until the required temperature and pressure have been built up in the cell. Thus, the time spent in treating the electrolyte and waiting for the cell to achieve the required temperature and pressure results in inefficient cell operation.
In the operation of high-pressure electrolytic cells, the prior art reveals methods of balancing gas and liquid electrolyte pressure within the pores of a porous electrode when the liquid electrolyte is static and not circulating.
The present invention allows for balancing liquid and gas pressure within the pores of a porous gas electrode in high-pressure electrolytic cell operation in which the liquid electrolyte is continuously being removed and fed to a cell without affecting cell operation. Therefore, a cell operated in accordance with the present invention may be operated at a high pressure without the need to shut down to treat or replace the electrolyte.